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目的观察天然抗氧化剂茶多酚 (TeaPolyphenols,TP)对模拟飞行低压吸纯氧引起的小鼠心肌自由基代谢异常的保护作用。方法 42只雄性昆明种小鼠随机分为 3组 (n =1 4) :对照组 (A)、550 0m低压吸氧组 (B)和TP保护组 (C)。B、C两组置于动物低压舱在 550 0m低压下吸氧 ( >96% ) ,2h/d ,3d/wk ,共 8wk。上舱暴露前 ,C组灌胃给予TP1 0 0mg/kg ,另 2组给予蒸馏水。末次实验后次日将小鼠断头处死 ,迅速取出心肌组织。测定心肌超氧化物歧化酶 (SOD)活性和丙二醛 (MDA)、一氧化氮 (NO)含量。另外 ,用免疫组化法对心肌组织Cu ,Zn -SOD和诱生型NO合酶 (iNOS)的含量进行定性观察。结果与对照比较 ,B组MDA水平、SOD活性和Cu ,Zn SOD酶含量明显升高 (P <0 .0 5) ;TP有明显保护作用 :降低MDA生成 (P <0 .0 1 ) ,SOD活性和含量恢复正常。与之相反 ,重复 550 0m低压吸氧暴露后 ,心肌NO含量和iNOS表达明显降低。重复给予TP使NO代谢恢复正常。结论天然抗氧化剂茶多酚对模拟飞行低压吸纯氧引起的心肌自由基代谢异常具有保护作用。
Objective To observe the protective effects of natural antioxidants Tea Polyphenols (TP) on myocardial metabolism of free radical in mice induced by simulated low pressure oxygen inhalation. Methods Forty - two male Kunming mice were randomly divided into three groups (n = 14): control group (A), 550 0m low pressure oxygen inhalation group (B) and TP protection group (C). Groups B and C were exposed to oxygen (> 96%), 2h / d, 3d / wk at 550m low pressure for 8wk. Before exposure to the upper chamber, group C was given TP1 0 0 mg / kg by gavage, and the other two groups were given distilled water. The mice were decapitated the next day after the last experiment and the myocardium was quickly removed. Myocardial superoxide dismutase (SOD) activity and malondialdehyde (MDA) and nitric oxide (NO) contents were determined. In addition, the content of Cu, Zn-SOD and iNOS in myocardium was qualitatively observed by immunohistochemistry. Results Compared with the control group, the level of MDA, the activity of SOD and the content of Cu, Zn SOD in group B were significantly increased (P <0. 05); the protective effect of TP was obvious: the level of MDA was decreased (P <0.01) Activity and content returned to normal. In contrast, NO exposure and iNOS expression were significantly reduced after repeated 550 0 m low-pressure oxygen exposure. Repeated administration of TP restored NO metabolism to normal. Conclusion The natural antioxidants tea polyphenols have a protective effect on myocardial free radical metabolism induced by simulated low pressure oxygen inhalation.